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M. J. Pellegrini-Cervantes,C. P. Barrios-Durstewitz,R. E. Nú,ñ,ez-Jaquez,F. J. Baldenebro-Lopez,R. Corral-Higuera,S. P. Arredondo-Rea,M. Rodriguez-Rodriguez,O. Llanes-Cardenas,R. Beltran-Chaco 한국탄소학회 2018 Carbon Letters Vol.26 No.-
Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of 4.0 A / m2 and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.
Espinoza-Moreno C. A.,Rodriguez-Rodriguez M.,Pellegrini-Cervantes M. J.,Barrios-Durstewitz C. P.,Núñez-Jaquez R. E.,Peinado-Guevara H. J.,Chinchillas-Chinchillas M.,Fajardo-San-Miguel G. 한국탄소학회 2021 Carbon Letters Vol.31 No.4
The use of recycled materials, such as the fne recycled aggregate made from concrete waste and carbon fber (CF) product of industrial waste, for the manufacture of conductive recycled mortars (CRM), transforms the mortar base cement normally made with cement:sand in a sustainable multifunctional material, conferring satisfactory mechanical and electrical properties for non-structural uses. This action provides ecological benefts, reducing the use of natural fne aggregates from rivers and the amount of concrete waste deposited in landflls resulting from construction waste. In this investigation the efect of the addition of CF on electrical properties in hardened, wet and dry state, electric percolation in dry state and fuidity of the wet mixture of a cement based CRM was evaluated: fne recycled aggregate: graphite powder, CRM specimens with dimensions of 4×4×16 cm. were manufactured for 3, 7 and 28 days of age and sand/cement ratios=1.00, graphite/cement=1.00, water/cement=0.60 and CF=0.1, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0% compared to the weight of cement. The results demonstrated the efect of the addition of CF in CRM, reducing fuidity of the mixtures due to the opposition generated by its physical interaction of CF with recycled sand or recycled fne aggregate and graphite powder (GP), in its case, placing the electric percolation percolation at 0.30% and 0.45% of CF for CRM with and without GP, respectively. Increases in electrical conductivity (EC) without the presence of GP are defned by the contact between the CF and the conductive paths formed. In contrast, with the presence of GP, the EC is defned by the contact between the CF and the GP simultaneously, forming conductive routes with greater performance in its EC.